1. Field of the Invention
The present invention relates to an image recording apparatus which records an image by jetting ink droplets to a recording medium.
2. Description of the Related Art
A common ink jet printer has an ink jet head which is provided on a carriage movable in a reciprocating manner in a predetermined scanning direction over a recording medium such as recording paper and the like and which jets ink(s) from a plurality of nozzles, and a transport mechanism which transports the recording medium in a transport direction perpendicular to the scanning direction. The printer alternately repeats an operation of jetting inks toward the recording medium while moving the ink jet head in the scanning direction, and another operation of transporting the recording medium in the transport direction by a predetermined transport amount or distance so as to record a desired image on the recording medium (for example, see Japanese Patent Application Laid-Open No. 2004-195749).
Here, as a method of image recording by the above-described ink jet printer, the following two methods are known: the method of jetting inks from the ink jet head only when the carriage moves in one of the scanning directions (single direction printing); and the method of jetting inks from the ink-jet head in both of the reciprocating scans of the carriage respectively (dual direction printing). Further, in the dual direction printing, there is also widely known a printing method in which dots are formed with a shorter interval than the nozzle layout interval in the transport direction, and thus an area to which liquid droplets are jetted in a preceding scan partially overlaps another area to which liquid droplets are jetted in the succeeding scan carried out after the scanning direction is reversed, so as to realize a high print resolution in the transport direction.